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== Protein synthesis RNAs ==
== Protein synthesis RNAs ==
== Messenger RNA ==
== Messenger RNA (mRNA) ==
[[File:MRNA structure.svg|thumb|650px|center|The structure of a mature eukaryotic mRNA. A fully processed mRNA includes a [[5' cap]], [[5' UTR]], [[coding region]], [[3' UTR]], and poly(A) tail. UTR = untranslated region]]
[[File:MRNA structure.svg|thumb|650px|center|The structure of a mature eukaryotic mRNA. A fully processed mRNA includes a [[5' cap]], [[5' UTR]], [[coding region]], [[3' UTR]], and poly(A) tail. UTR = untranslated region]]
[[Transfer RNA]] ('''tRNA''') is a short molecule of about 80 [[nucleotide]]s which carries a specific amino acid to the polypeptide chain (the protein being made) at a [[ribosome]]. There is a different tRNA for each amino acid. Each one has a site for the amino acid to attach and an anti-codon to match the codon on the mRNA. For example, [[codon]]s UUU or UUC code for the amino acid [[phenylalanine]].<ref>{{cite web |title=Transfer RNA (tRNA) |url=https://www.genome.gov/genetics-glossary/Transfer-RNA |website=National Human Genome Research Institute |accessdate=4 February 2024}}</ref>
[[Transfer RNA]] ('''tRNA''') is a short molecule of about 80 [[nucleotide]]s which carries a specific amino acid to the polypeptide chain (the protein being made) at a [[ribosome]]. There is a different tRNA for each amino acid. Each one has a site for the amino acid to attach and an anti-codon to match the codon on the mRNA. For example, [[codon]]s UUU or UUC code for the amino acid [[phenylalanine]].<ref>{{cite web |title=Transfer RNA (tRNA) |url=https://www.genome.gov/genetics-glossary/Transfer-RNA |website=National Human Genome Research Institute |accessdate=4 February 2024}}</ref>
== rRNA ==
== rRNA ==
'''Ribosomal RNA''' ('''rRNA''') is the [[Catalysis|catalytic]] component of the ribosomes. [[Eukaryote|Eukaryotic]] ribosomes contain four different rRNA molecules: 18S, 5.8S, 28S and 5S rRNA. Three of the rRNA molecules are synthesized in the [[nucleolus]], and one is synthesized elsewhere. In the cytoplasm, ribosomal RNA and protein combine to form a nucleoprotein called a ribosome. The ribosome binds mRNA and carries out protein synthesis. Several ribosomes may be attached to a single mRNA at any time.<ref name=The_Cell>{{cite book | title=The Cell: a molecular approach| edition=3rd| author=Cooper GC & Hausman RE| date=2004| pages=261–76, 297, 339–44| publisher=Sinauer| isbn=0-87893-214-3 | oclc=174924833|id=OCLC 52121379 52359301 56050609}}</ref> rRNA is extremely abundant and makes up 80% of the 10 mg/ml RNA found in a typical eukaryotic [[cytoplasm]].<ref>{{cite journal | author=Kampers T. | display-authors = etal | title=RNA stimulates aggregation of microtubule-associated protein tau into Alzheimer-like paired helical filaments| journal=FEBS Letters| year=1996| volume=399 | pages = 344–349| pmid=8985176 | doi = 10.1016/S0014-5793(96)01386-5 | issue=3| s2cid = 1722620 }}</ref>
'''Ribosomal RNA''' ('''rRNA''') is the [[Catalysis|catalytic]] component of the ribosomes. [[Eukaryote|Eukaryotic]] ribosomes contain four different rRNA molecules: 18S, 5.8S, 28S and 5S rRNA. Three of the rRNA molecules are synthesized in the [[nucleolus]], and one is synthesized elsewhere. In the cytoplasm, ribosomal RNA and protein combine to form a nucleoprotein called a ribosome. The ribosome binds mRNA and carries out protein synthesis. Several ribosomes may be attached to a single mRNA at any time.<ref name=The_Cell>{{cite book | title=The Cell: a molecular approach| edition=3rd| author=Cooper GC & Hausman RE| date=2004| pages=261–76, 297, 339–44| publisher=Sinauer| isbn=0-87893-214-3 | oclc=174924833|id=OCLC 52121379 52359301 56050609}}</ref> rRNA is extremely abundant and makes up 80% of the 10 mg/ml RNA found in a typical eukaryotic [[cytoplasm]].<ref>{{cite journal | author=Kampers T. | display-authors = etal | title=RNA stimulates aggregation of microtubule-associated protein tau into Alzheimer-like paired helical filaments| url=https://archive.org/details/sim_febs-letters_1996-12-16_399_3/page/344 | journal=FEBS Letters| year=1996| volume=399 | pages = 344–349| pmid=8985176 | doi = 10.1016/S0014-5793(96)01386-5 | issue=3| s2cid = 1722620 }}</ref>
== snRNAs ==
== snRNAs ==
[[Small nuclear RNA]]s ('''snRNA''') join with proteins to form [[spliceosome]]s. The spliceosomes govern [[alternative splicing]]. Genes code for proteins in bits called [[exon]]s. The bits can be joined together in different ways to make different mRNAs. Thus, from one gene many proteins can be made. This is the process of alternative splicing. Any unwanted versions of the protein get chopped up by [[protease]]s, and the chemical bits re-used.
[[Small nuclear RNA]]s ('''snRNA''') join with proteins to form [[spliceosome]]s. The spliceosomes govern [[alternative splicing]]. Genes code for proteins in bits called [[exon]]s. The bits can be joined together in different ways to make different mRNAs. Thus, from one gene many proteins can be made. This is the process of alternative splicing. Any unwanted versions of the protein get chopped up by [[protease]]s, and the chemical bits re-used.
Micro RNAs (miRNA) act by joining an enzyme and blocking mRNA or speeding its breakdown. This is called [[RNA interference]].<ref>[https://web.archive.org/web/20070120113455/http://nobelprize.org/nobel_prizes/medicine/laureates/2006/adv.html The Nobel Prize in Physiology or Medicine 2006. RNA Interference]</ref><ref>Lee R.C. & Ambros V. 2001. An extensive class of small RNAs in Caenorhabditis elegans. ''Science'' '''294''', 862-864.</ref><ref>Lau N.C. ''et al'' 2001. An abundant class of tiny RNAs with probable regulatory roles in Caenorhabditis elegans. ''Science'' '''294''', 858-862.</ref>
Micro RNAs (miRNA) act by joining an enzyme and blocking mRNA or speeding its breakdown. This is called [[RNA interference]].<ref>[https://web.archive.org/web/20070120113455/http://nobelprize.org/nobel_prizes/medicine/laureates/2006/adv.html The Nobel Prize in Physiology or Medicine 2006. RNA Interference]</ref><ref>Lee R.C. & Ambros V. 2001. An extensive class of small RNAs in Caenorhabditis elegans. ''Science'' '''294''', 862-864.</ref><ref>Lau N.C. ''et al'' 2001. An abundant class of tiny RNAs with probable regulatory roles in Caenorhabditis elegans. ''Science'' '''294''', 858-862.</ref>
== siRNA ==
== siRNA ==
Small interfering RNAs (sometimes called silencing RNAs) interfere with the expression of a specific gene. They are quite small (20/25 nucleotides) double-stranded molecules. Their discovery has caused a surge in biomedical research and drug development.<ref>{{cite journal |author=Hamilton A. & Baulcombe D |title=A species of small antisense RNA in posttranscriptional gene silencing in plants |journal=Science |volume=286 |issue= 5441|pages=950–2 |year=1999 |pmid=10542148 |doi=10.1126/science.286.5441.950}} First description of siRNAs.</ref><ref>{{cite journal |author=Hannon G. & Rossi J |title=Unlocking the potential of the human genome with RNA interference |journal=Nature |volume=431 |issue= 7006|pages=371–8 |year=2004 |url=http://www.nature.com/nature/journal/v431/n7006/full/nature02870.html |doi =10.1038/nature02870 |pmid=15372045|bibcode=2004Natur.431..371H |s2cid=4410723 }}</ref>
Small interfering RNAs (sometimes called silencing RNAs) interfere with the expression of a specific gene. They are quite small (20/25 nucleotides) double-stranded molecules. Their discovery has caused a surge in biomedical research and drug development.<ref>{{cite journal |author=Hamilton A. & Baulcombe D |title=A species of small antisense RNA in posttranscriptional gene silencing in plants |url=https://archive.org/details/sim_science_1999-10-29_286_5441/page/950 |journal=Science |volume=286 |issue= 5441|pages=950–2 |year=1999 |pmid=10542148 |doi=10.1126/science.286.5441.950}} First description of siRNAs.</ref><ref>{{cite journal |author=Hannon G. & Rossi J |title=Unlocking the potential of the human genome with RNA interference |journal=Nature |volume=431 |issue= 7006|pages=371–8 |year=2004 |url=http://www.nature.com/nature/journal/v431/n7006/full/nature02870.html |doi =10.1038/nature02870 |pmid=15372045|bibcode=2004Natur.431..371H |s2cid=4410723 }}</ref>
== Parasitic and other RNAs ==
== Parasitic and other RNAs ==